Antihunting means for remotecontrol systems



-July 5, 1949. M. N. YARDENY 2,475,269

ANTIHUNTING MEANS FOR REMOTE-CONTROL SYSTEMS Filed Feb. 27, 1943JNVENToR.

MICHEL N. MRDENY 50' l 1110 M55 OY M W Patented July 5, 1949 UNITEDSTATES PATENT OFFICE ANTIHUNTING MEANS FOR REMOTE- CONTROL SYSTEMSMichel' N. Yard'eny, New York, N. Y.

Application February'27, 1943, Serial No. 477,469

4 Claims. l

My invention relates tol remote control systems and has particularreference tok systems employing electricmotors with control devices forbring ing two or morev controlled members into exactrequire'dposit-icn's.

My invention has further' referencey 'to-control systemsappara-tus inwhiclri al reversible electric motor isemployed for operatingA a use'-ful load, said motor having reversing windings connected directly rorthrough a suitable relay or relays with twor control elements forproducing relative movements between the lcont-rol elements, one-.of thecontrol elements comprising4 a1 pairl off conducting members separatedby a.. gap andithe otheracontactor in;1 aL slidingl engagement withLthe. conducting members, the motor being so connected. in al circuitwith? the control elements that it is stopped when thecontacterengagesthefgap.

One off thee main` objects of' my: invention is to provide an apparatuslorsystem' whereby: a useful.4 load can be. moved. al predeterminednumber of complete' revolutionsand then `adesired fram tion of onevrevolution for one cycle: of move ment ofithecontrol elements.Anapparatus of this type may 4be described as a multi-revolution device.

Anothery object` of :'my: inventionI isV to provide means for placingtheconducting members accurately ini any desired. position,l each pair ofconducting members being` capable of being adjusted withinalmost. 360.oor almost a complete circle.

Another object of my inventionisvto reduce sparking at the contactsbetweenthe conducting members andthe contacts When-rotation of themotory is. reversed y or when thecmotor is stopped. Ii accomplishthisfby using special relays: consuming a. verysmall amountof electricpower; alsoby using condensersv and resistors in the currentinterrupting circuits.

.Anotherf'objectiotmy invention isto provide an apparatusvof.thefff'oregoing general typel with further improvements. for. itssatisfactory operation.v Onev of such. important improvements consistsinsth'eprovision 'for suppressing and en-V tirelyKeliminatingeosci'llations.or hunting of fthe motor: when the.conta'ctor'. engag'esthegap .and the motonmust be' stopped.` If haveyfound'by actual experience that 4such-afresultcan be ob'- tained when.using a "combinationA of certain *elec-A trical and mechanical.features -as .disclosed -more fully in the' appended specification.Certain of these features can' be. used, however, not only with theremote control systems but also with other systems employing reversingmotors.

I also provide means to combine electric with manualcontro'ls, to beused selectively, the oscillation-suppressing features beingautomatically eliminated when the manual control is used.

My invention is more fully described in the accompanying specication anddrawings in which Fig. 1 is a diagrammatic view of my remote controlsystem in one of its modifications;

Fig. 2 is a similar diagrammatic View of the system, showing electrical'connections;

Fig. 3- is a detail view of a driving gear and friction clutch, taken ontheiine 3 3 of Fig. 2;

Fig. 4 is a diagrammatic View of a system with a shunt motor; and

Fig. 5 is a detailed view of an arrangement of the control elements.

My remote control system is represented in one of its modiiic'ations inFigs. 1, 2 and 3, Fig. 2 showing the complete circuit diagram. Itconsists of a reversible electric motor With reversing windings 2, '3,Fig. 2. The windings are connectedatl the common tap 4 by'a lead and aninterruptor 5U, 5|', 52 or leads 93, 94 and a rotary 'switch 53, 55, 56,5l as` will be explained more fully l'ierein'a'fter;y 5 with oneterminal of asource of cur-rent 6, the other terminal being connected bya lead-l with a `contacter 8. The latter can be 'placed in-any desiredposition by a manually or otherwisecont'rolled device 9, indicated dia'-grammatically vin` Fig. 1. The contactor has a pointer= lindicatingitsposition on a scale The contactor also hasla contact'point I2 adaptedto'bridgelthe gaply I3 between members I4, I5., made of aconvducting'-`v material and which may bein theformofy segments so thatthey Will be for convenience'called segments. The segmentsareuc'onnec'ted'by flexible leads I6, H with the endsi'of the coilsil,|9of`a suitable'r'elay acting on'switches 20, 2| for causing theswitches toengage contact pointsl 22,' 23, connected through a'lead1241Wi1th the' second terminal of the'sourc'e 'of'c'urrent' Normally'the switches 20, 2| engage contact points 22', 23 ofthe coils 2, 3.- Itwill be seen-'that current will flow through vvone of l4therelay'fcoilsI8 or'- |9 when the contact' member engages by its pointedy l2 one ofIthe'segments I4" or l5. The' corresponding switch 20 or12f| will bethen attracted vby the en ergized relay coil, causingV the current alsoto flow' through' one of the motoreldwindings 21er 3: The motoriwillrotatein a 'corresponding."r direction, turning the segments throughworm 25 and 21 and worm gears 26, 24' or through some other geararrangement. The pinion 25 may be connected by a shaft 29 with a usefulload 38 which may be a tuning condenser, etc. The rotation will continueuntil the gap I3 is bridged by the contact member I2 whereby -both relaycoils will be energized with a result that both switches 2D, 2l will bedeflected, disconnecting the motor windings 2, 3. The motor will betherefore, deenergized and stopped. The gap portion I3 is narrower thanmain gap I3 so as slightly to enlarge the extent of the contact surfacesI4, I5 and thus somewhat to increase the range of the possible positionsof the disk, thereby also increasing the range of the possible loadpositions.

The segments are suitably mounted on a comn mon shaft 29' with the gear24', concentric with the shaft 28 of the contactor 8.

With the double gear reduction as shown, the shaft 29 of the load 38will make several revolu tions for one revolution of the indicator I6.It will be therefore possible to turn the shaft 29 through severalrevolutions and to stop the same exactly in a desired position asindicated by the pointer I0 on the scale I l.

Since it is preferable to use a small high speed motor with my system,it is also necessary to take steps to prevent overrunning of theindicated position by the rotating members by inertia, which overrunningmay result in oscillations or hunting of the motor. One of such devicesfor suppressing motor oscillations is shown. in Figs. 1 and 2 andconsists of a flywheel 3l, freely rotatng on the motor shaft 28 butconnected with the shaft by a friction clutch 32, pressed against theside of the Iiywheel by a spring 33. Pressure of the spring may beregulated by a nut 34. The effect of the iiywheel is such that it willcause an increased drag on the shaft when the motor a rotation isreversed, tending to retard the rotation after reversals and therebystopping the hunting or oscillations.

An additional hunting-suppressing means consists of a frictional clutchbetween the gear 26 and shaft 29 as shown in Fig. 3. The gear is looselymounted on the shaft 29 but prevented from rotation by a pin 35 engaginga slot 36. The latter, however, is sufficiently wide to allow for acertain amount of free motion of the gear 0n the shaft. The gear isfurther engaged to the shaft by a friction clutch plate 31, slidablykeyed to the shaft 29 and urged by a spring 38 against the face of thegear. Spring tension can be adjusted by a nut 39, Fig. 3.

Tension of the clutch is so adjusted in relation to the resilientfriction of the contact member I2 in the gap that the clutch will slidewhen the motor is deenergized by the gap being bridged by the Contactmember I2 and the motor continues to rotate by inertia only. The contactmember will therefore be locked in the gap without any back and forthoscillations. Clutch friction will dissipate the inertia rotationalenergy of the motor, eiectively stopping the latter while it is stilldeenergized.

Gears 40, 4I are provided for manual operation of the device as shown inFig. 1. The gear 4I is mounted on a shaft 42, sliding in bearings 43 andbeing urged upward by a spring 44. The shaft can be rotated by a thumbhead or handle 45 after it is depressed for bringing the gear 4I intoengagement with gear 40. At the same time a cam 46 mounted on the shaft42 engages one end of a lever 41 whose other end is pivoted at 48, themiddle portion of the lever engaging a cup-shaped member 85, Fig. 3,with teeth 86, engaging corresponding holes 81 in the gear 26. A spring88 normally keeps the cup-shaped or toothed member away from the gear.With this arrangement the lost motion between the gear and the shaft 29is eliminated when the manual control is used, the toothed member 85being slidably keyed on the hub of the clutch member 31.

As an added arrangement for eliminating lost motion between the gear 26and worm 21, the gear may be made of two parallel discs 26', 26, slidingin relation to each other but connected together by helical springs 49fitted in slots 43'. The springs are given initial tension when the gearis brought into mesh with the worm, causing the two halves of the gearto press at the worm teeth from the opposite directions.

I have also found that motor hunting is also largely suppressed when twosuccessive worm drives are employed as shown in Fig. 2, because of theincreased friction of such drives.

As an additional means to suppress oscillations I use a vibratinginterrupter 5U, Fig. 2, connected in series with the motor in the lead5. Current passes through the interrupter coil, vibrating armature orarm 5i, and contact point 52 to which the armature is urged by a spring89. A resistor 50 is connected parallel to point 52 to suppresssparking. The interrupter is normally short circuited by Wires 93, 94,extending to contact points 53, 51. The motor shaft consists of twoportions, 28 and 54, connected together by a hook 55 on the shaft 28engaging a lug 56 on the shaft 54. The points 53, 51 are in electricContact with each other as long as the shaft 28 drives the shaft 54 inone or the other direction, but as soon as direction of rotationchanges, i. e., when the contactor I2 passes over the gap to the nextsegment I4 or I5, the hook 55 leaves the lug 56 and makes one revolutionbefore engaging the lug again from the other side. In the meantime theleads 93, 94 are disconnected so that the Vibrator becomes operative,effectively stopping the motor when the contactor reaches the gap.

The effect of the vibrator is such that the motor is slowed down whenthe contactor engages the segments at the gap, thereby losing itstendency to oscillate, rapidly reversing its rotation.

A lamp 60 or other suitable signal device can be placed in the motorcircuit to indicate operation of the device.

A fri-ctional clutch 58 (see Fig. 1) may be also provided between theshaft 54 and the worm so adjusted that the motor can drive the loadthrough the clutch, but when manual means is used for turning the worm21, the clutch permits rotation of the worm without turning the motorshafts 28 and 54. Voltage for the relays may be reduced by the use of apotentiometer I43 or similar device such as transformer, etc.

To increase the accuracy of the control and as means to suppress motoroscillations or hunting of the motor, provisions may be provided toincrease friction between the contactor and the conducting segments atthe gap. Such arrangements are shown in Fig. 5 and consist in raisingthe edges |38 of the segments I4 and I5. Such arrangements are ofparticular advantage when thin segments are used to avoid deflection ofthe segments by the pressure of the contactor. The edges are raised atthe main gap I3 only, the

other gap I3' being narrow, this gap never being bridged by the point I2of the contactor 8.

To increase the accuracy of the system and as an additional means tosuppress motor oscillations, provision is made to increase frictionbetween the conductor and the conducting segments at the gap. Accordingto Fig. 5, the edges of segments I4 and I5 forming gap I3 therebetweenare raised at |38. The tips of the segments are bent downwardly to restupon disk 12, thereby avoiding deflection of the engaged segments by thecontact pressure.

As shown in Fig. 4 coil 5U is connected by means of leads 93, 94 tocontact brushes 53, 51 engaging contact rings 91, 98 on the hubs of lug56 and of hook 55. f

A direct current motor I 48 can be used with my system as shown in Fig.4, current passing through the armature of the motor through leads I4I,|42. A spark suppressing resistor |41 is lncluded in the armaturecircuit. When one of ythe shunt iield windings 2 or 3 is energized, the

resistor is short circuited by a magnet |44, connecting the switch arm|45 directly with a lead |46. The transmission between motor |48 andsegments I 4, I5 is shown only diagrammatically and is of the same typeas illustrated in Fig. 2.

I claim as my invention:

l. A control apparatus comprising relatively movable control elements;reversible drive means adapted to operate a useful load; transmissionmeans arranged to be operated by the drive means for producing relativemovement between the control elements, said transmission means beingarranged to cause the control elements to complete one cycle of movementfor more than one cycle of movement of the drive means; means to controlthe drive means by the relative position of the control elements, and torender the drive means inoperative in response to the control elementsoccupying a predetermined relative position; and anti-hunting meanscomprising means for reducing the rate of movement of the drive meansand means for rendering the reducing means operative for a fraction ofone cycle of movement of the drive means in response to a reversal ofthe drive means.

2. A control apparatus comprising relatively movable control elements; amotor; reversible rotary drive means operated by the motor and arrangedto operate a useful load; transmission means arranged to be operated bythe drive means for producing relative movement between the controlelements, said transmission means being arranged to cause the controlelements to complete one cycle of movement for more than one cycle ofmovement of the drive means; means to control the direction of movementof the drive means by the relative position of the control elements andto render the motor inoperative in response to the control elementsoccupying a predetermined relative position; and anti-hunting meanscomprising means to reduce the rate of rotation of the motor byperiodically interrupting its energy input and means to render theantihunting means operative for a fraction of one revolution of thedrive means in response to the reversal of the direction of rotation ofthe drive means.

3. A control apparatus comprising relatively movable control elements;reversible drive means adapted to operate a useful load; transmissionmeans arranged to be operated by the drive means for producing relativemovement between the control elements, said transmission means beingarranged to cause the control elements to complete one cycle of movementfor more than one cycle of movement of the drive means; means to controlthe drive means by the relative position of the control elements, and torender the drive means inoperative in response to the control elementoccupying a predetermined relative position; and anti-hunting meanscomprising means for reducing the rate of movement of the drive meansand means for rendering the reducing means operative for a fraction ofone cycle of movement of the drive means.

4. A control apparatus comprising relatively movable electric controlelements; a reversible motor adapted to operate a useful load;transmission means arranged to be operated by the motor for producingrelative movement between the control elements, circuit means to controlthe motor by the relative position of the control elements, and torender the motor inoperative for the purposes aforesaid in response tothe control elements occupying a predetermined relative position, thesaid transmission having a driving portion and a driven portion, dogssecured to the said portions and arranged with the driving dog inabutting driving relation with the driven dog, electric means forreducing the speed of the said motor included in a circuit with themotor, and a by-pass circuit including the said dogs and speed reducingmeans, the said driving abutment between the dogs completing the saidby-pass circuit to render the speed reducing means normally ineffectiveand breaking the said by-pass circuit during the time the driving dog isdisengaged from the driven dog upon reversal of motor rotation.

MICHEL N. YARDENY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 645,766 Sundh Mar. 20, 19001,271,362 Rainey July 2, 1918 2,094,777 Ellinger Oct. 5, 1937 2,204,065Beizer et a1 June 11, 1940 2,331,354 Stout Oct. 12, 1943 2,342,717Yardeny a Feb. 29, 1944

